Detachable coupling



Och 1949- A. P. BUFFINGTON DETACHABLE COUPLING Filed Aug. 22, 1946 INVEN TOR. gym/2 flUfH/VTU/V I AG'f/Vl') v engagement. with a shaftn ,and ma Patented Oct. 11, 1949 D T HAB 0.96111-1111or ain-1 Bufiin mn Philco Corporatqtat ne ins y Bh dnhia, Pa -1 s n) adel hia-lie a: o.

ApplicationAugustZZ, 1946;: SerialiNo. 692398 8,C laims, (Cl. 237 -53).

releasedandwremovedtherefrom.

In-. certaintypes oi'sapparatus, particularly; in radio. or; -.-other=releotrioal-;- apparatus, there 1 are utilized 'scontrola; shafts, which z-projeet outwardly fromahousingsoncabinettintooengagement-witha suitablehknob or ;oth;er. \operatingelement; to be driventhereby.- Manufactured and assembly of such apparatus;,as well iasrepairand replacement of partsthereofinan -begreatly: iacilitated by the .use ot-knobg-and shaft devices of such an-ature thatassembly may be made; merelybywfitting the knob over theefree end Oftheshaft;without resort to-guideways,. set. screws'or. theelikem Although such devices-have been- '.dc 2.vised,: they-1 have fre: quently been'rswbject- 713G; difli'culties and disade vantages, in that it;is;necessaryn to achieveesecure. retentionof the ;knob upon the shaft {finch-1305i; five-driving! engagement-;between these elements; While at the same time permitting ready:,dis,; association-1.-of-rthe. two par. The presentiinvention hasasan object -.the,,p1:o-, vision -.of, a :novel and .im-proved knob,- and :shaft assembly; of suohiaanature,thatdrelative coupling and uncoupling thereof-. may her accomplishedein thecsimplestppossiblemanner.-

Itisla .furth'er-t object of this invention -.-to pro videa knob-whichtmay be readily and -inex=pen- 'sively-manufactured; as -by- -a molding operation; which knob-includesan elemen-teffectiveto automatically establish'-- positivedriving connection with an -associated shaft;- the connection being such that; while inadvertent disassociation o f -the kno b frorn the shaft is not-possibleduring normal usage the knob may be easily removed by: ei fecting; a special rotary manipulation thereof.

The invention also has as an object the pro; sion pi no ndi a t: a semb y n YWh QZKQQ 09. 5: re e uiredi ur n the m91 l1tine,, 1c,, Y

emovalpf hei nqh;

The manner in which the foregoing objeets ediadraataeesr e ealiz dnwi lp w "be t unde too by e er n e oithe q qwin vs i a n, an dared he gh of h rew n nwl1i Figure 1 is as, sidev elevational view ,7 of a knob and; haf s emb e o t -l ttedt inna c rda e with t eme entinrntwma ort qepi hek 9b ain i-bmke iavavto i ailitat lust /tiem;

. 2 u e. 2 e eetiqee la 01 has S e a a t; free a .L

ur ce-f xt idi JaXI nthe s i v .wayw oeia allmof saidshait; andadap es osc iperete wit nob a n n element-przn ins 1- na m nn e ntly tdbe described. The nob, es enet dwat .BJ Q PI prises taehead portion 9; which; is manipulatedby thepoperatorg duringadjustments of the shaft 5, and a collar portion l0 having an internal diameter of a size to fit over region -.ofzsaid -;p1ane1surface i 6 In particular accordanceewiththe present in vention thev-iaforementionedaretaining =-e1ement-; 1 comprisea a-relatively stifiuresilient; member, of steels;orelikeematerial; having one end I! fixedly secured .wvithin -'bhe. C01l2,I I flzland a blade. portion 12' normally extending lbaclrwardly. within the knob, atean angleuofaapproximately 45 degrees with respect totheshaft. Thisangle is such that the knobmay be-readily slipped over the end of the-shaft; with' the bladea.l2uslidine; across the fiat provided bythe surface 6r The, blade of the retaining element is relativelythin and, accordingly,- any attempt to pull theknob 01f the 'shaft 'cause'sl the free-edgeof'theblade (represented -at' l3--*-in-Figures- 2 anda) and particularly the corner portion. I 4,--'to diginto the surface 6 and-thereby prevent'removal-of the knob A. t airfare fi ures 2 tthe blade porti lz bears upon the surface ii through; a ens der h ad stam i nw il rthe r under bein usn e .f.t ..res ient p e sure eith a e, reientrelatwerotat onal mov e t o the o t. haituaq re ltn9 m pe ditiqn o h perer 9 hisjexte d be new-Matt also in e u red. when, t e, knob, s awe. nelt utomat ally n h m0 i u e at' n, I ntwhiqh, the is o et ahla e sii e nta lt said shaft r 5 in zthe tance, as represented in Figure 3, until an upwardly curled low friction surface-portion 15 of the retaining element or blade bears upon the surface 6. While such small additional rotation of the knob may be readily effected, it will be understood that such movement should be sufficient to insure that the knob will not be rotated to this position,"inadvertently. When the position illustrated in Figure 3 has been v reached, the relatively sharp edge portion l3 no' longer bears against surface 6-only therounded surface l making contact with the shaft-and the knob may then be slipped from the cient torque being maintained to retain the portion l5 in contact with said surface 6. It will be appreciated that the portion l5 may take other forms, the important factor being the relatively low friction of the surface. Q

I From the foregoing description, it will be understood that the present invention provides a novel and advantageousknob and shaft assembly,

is effected against the resilience of the blade l2, which resilience,

in which mounting and removal of the knob may v beeffected in an extremely simple'manner.

,While a preferred embodiment has been illustrated in the drawings and described'in the specification, it will be understood that the invention is susceptible of certain modifications without departing from the essential spirit thereof. For example, the retaining element or blade I might be secured to the shaft 5, and a suitable flatted portion be provided in the collar 10 against which the free end of the resilient blade would bear. However, it will be understood that such changes and modifications are contemplated as'may come within the terms of the appended claims.

I claim:

1. In a disconnectable coupling assembly, a pair of disconnectable elements, a coupling member secured to one of said elements and having a relatively high friction surface-portion normally bearing resiliently against the other of said elements and preventing movementstending to disconnect said elements,'and lowfriction means disposed out of contact with said other element when said high frictionsurface portion is in contact therewith, said elements being relatively rotatable through a small angle against the resilient pressure aforesaid, such rotation acting both to move said high friction surface portion out of contact with the said other element and to bring said low friction means into contact therewith, whereby to provide for disconnection movements of said elements.

2. In a disconnectable coupling assembly, a pair of disconnectable elements, a coupling member secured to one of said elements and having a relatively sharp edge normally bearing resiliently against the other of said elements, said edge normally impinging against said other element at such an angle as to prevent movements tending to disconnect said elements, and low friction means disposed out of contact with said other element when such sharp edge is in contact therewith, and said elements being relatively rotatable through a small angle against the resilient pressure of said member, such rotation acting both to move said edge out of contact with the said otherelement and to bring said low friction means'into contact therewith, whereby to provide for sliding of said member across said other element and disconnection of the assembly.

3. A disconnectable coupling assembly, comprising a pair of disconnectable elements, and a spring leaf secured to one of said elements and having a relatively sharp edge normally bearing resiliently against the other of said elements, said: edge normally impinging against said other element at such an angle as to prevent movements tending to disconnect said elements, said spring leaf fur- --ther having a relatively smooth rounded surface disposed out of contact with said other element when said sharp edge is in contact therewith, and

said elements being relatively rotatable through a a small angle against the resilient pressure of said spring leaf, such rotation acting both to move said edge out of contact with said other element and to bring said rounded surface into contact therewith, whereby to provide for sliding of said leaf across said other element and disconnection of the assembly. v

4. In a control knob adapted for disconnectable association with a shaft, to be driven thereby, a portion adapted to surround an end of the shaft, and coupling means secured within said portion and disposed to bear resiliently against the shaft inserted within said portion and resist relative rotation between the knob and shaft, said means further being effective to create a high frictional resistance to relative axial movement between said knob and the shaft whereby to prevent withdrawal of said knob from the shaft under normal conditions of operation, said means further having a low friction surface-portion so located as normally to be disposed out of contact with the shaft, said knob being adapted for rotation through a small angle with respect to the associated shaft against the resilient pressure of said means to substantially eliminate said high frictional resistance and to bring said low friction surface-portion into contact with the shaft; whereby to provide for sliding of said means along the shaft and removal of the knob therefrom.

5. In a control knob adapted for disconnectable association with a shaft to be driven thereby, a portion adapted to surround an end of the shaft, and. a coupling spring leaf secured within said portion and having an edge adapted to bear re siliently against the shaft and resist relative rotation between the knob and shaft, said edge being relatively sharp and so disposed as to impinge against the shaft at such an angle as to prevent withdrawal of the knob from the shaft under normal conditions of operation, said springleaf further having a rounded surface so located as to be disposed out of contact with the shaftwhen said edge is in bearing engagement therewith, said knob being adapted for rotation through a small angle With respect to the associated shaft against the resilient pressure of said spring leaf both to move said edge out of contact with the shaft and to bring said rounded surface into cone tact therewith, whereby to provide for sliding of said spring leaf along the shaft and removal of the knob therefrom.

6. In a control knob adapted for disconnectable association with a shaft to be driven thereby, interior wall structure defining .an open-ended shaft-receiving portion, and a resilient member having one end carried by said wall structure, and another end extending from said wall structure laterally into said shaft-receiving portion and rearwardly with respect to the open end thereof,

said other end being provided with both a relatively sharp edge adapted to bear resiliently against the shaft and with a low friction surfaceportion so located with respect to said sharp edge as to be disposed out of contact with the shaft when said sharp edge is in bearing engagement therewith, the construction being such that slight rotation of the knob with respect to the shaft will move said sharp edge out of contact with the shaft and bring said low friction surfaceportion into contact therewith.

7. In a disconnectable knob and shaft assembly, a knob provided with interior wall structure defining an open-ended shaft-receiving portion, a shaft having an end portion disposed within said shaft-receiving portion, said end portion having an axial cut providing a substantially flat surface in general parallelism with the axis of the shaft and spaced from the said interior wall structure, and a spring leaf carried by said wall structure and extending therefrom laterally into said shaftreceiving portion and rearwardly with respect to the open end thereof, the free end of said leaf being provided with both a relatively sharp edge bearing resiliently against the said flat surface and with a low friction surface-portion so located with respect to said sharp edge as to be disposed out of contact with said flat surface when said sharp edge is in bearing engagement therewith, said knob and shaft being relatively rotatable through a small angle against the resilient pressure of said leaf, such rotation acting both to move said sharp edge out of contact with the said flat surface and to bring said low friction surfaceportion into contact therewith.

8. In a disconnectable coupling assembly, a pair of disconnectable elements, a coupling member interposed between said elements and having a relatively high friction surface-portion normally bearing resiliently against one of said elements and preventing movements tending to disconnect said elements, and low friction means disposed out of contact with the said one element when said high friction surface-portion is in contact therewith, said elements being relatively rotatable through a small angle against the resilient pressure aforesaid, such rotation acting both to move said high friction surface-portion out of contact with the said one element and to bring said low friction means into contact therewith, whereby to provide for disconnection movements of said elements.

ALAN P. BUFFINGTON.

REFERENCES CITED UNITED STATES PATENTS Name Date Young May 10, 1938 Number 

